CommonLogLoader is used to load logs based on Apache's common log format, based on a format like
LogFormat "%h %l %u %t \"%r\" %>s %b" common
The log filename ends up being access_log from a line like
CustomLog logs/access_log common
Example:
raw = LOAD 'access_log' USING org.apache.pig.piggybank.storage.apachelog.CommongLogLoader AS (remoteAddr,
remoteLogname, user, time, method, uri, proto, bytes);